Re: [PATCH v4 03/15] rtc: rzn1: Fix weekday underflow when alarm crosses month boundary
Wolfram Sang <[email protected]>
| Newsgroups | dev.linux.lists.sashiko-reviews,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-rtc |
|---|---|
| Message-ID | <aoWpLvrNGHBPvFY5@shikoro> |
> [Severity: High] > This is a pre-existing issue, but does this time_after() comparison > allow bypassing the 1-week hardware limit on 32-bit systems? This is fixed later. > [Severity: Medium] > This is a pre-existing issue, but what happens if the RZN1_RTC_ALW register > is uninitialized and wday is 0? > > Calling fls(0) - 1 would evaluate to -1. If the current time is a Saturday > (tm_now.tm_wday == 6), delta_days evaluates to 0, which bypasses > the if (delta_days) block and leaves tm->tm_wday = -1. > > Since the core function rtc_valid_tm() does not check tm_wday, would this > propagate a bogus alarm date to the caller? This looks worth investigating to me. On RZN1, ALW is default 0.
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